net: context: Fix the connect check for IPv4

Make sure that we cannot connect to IPv4 multicast or broadcast
destination address for a TCP socket.

Signed-off-by: Jukka Rissanen <[email protected]>

Author: jukkar

subsys/net/ip/net_context.c

@@ -1324,7 +1324,13 @@ int net_context_connect(struct net_context *context,
 			goto unlock;
 		}
 
-		/* FIXME - Add multicast and broadcast address check */
+		if (net_context_get_proto(context) == IPPROTO_TCP &&
+		    (net_ipv4_is_addr_mcast(&addr4->sin_addr) ||
+		     net_ipv4_is_addr_bcast(net_context_get_iface(context),
+					    &addr4->sin_addr))) {
+			ret = -EADDRNOTAVAIL;
+			goto unlock;
+		}
 
 		memcpy(&addr4->sin_addr, &net_sin(addr)->sin_addr,
 		       sizeof(struct in_addr));